Steps to reproduce:

1. Open the linked project (or set up a project for HDRP usage from https://github.com/Unity-Technologies/ScriptableRenderPipeline)
2. Make sure Metal Support for editor is enabled
3. Open 'TransparencyTest' scene
4. Hit Play
5. Navigate to any of the transparent objects, doesn't matter, issue seen on pretty much all of them
6. Notice the ones near edges of the screen are cut-off (see screenshots)

This is somewhat happening on Windows (DX11) as well, though instead of the camera's background color, the objects just seem less transparent on the edges.